Clean the bones and beef thoroughly.

Place the bones in a pot, cover with water, add vinegar, and bring to a boil for 15 minutes.

Discard the water used to boil the bones and rinse the bones and beef again to clean.

Put the bones in a pressure cooker, add 12 3/4 cups of water, and simmer until the pressure cooker reaches full pressure, then turn off the heat. If simmering bones with meat, remove the meat after reaching full pressure twice, let it cool, and continue simmering the bones 2-3 more times to extract all the flavors. Roast the dried onion, ginger, black cardamom, cinnamon, and star anise.

Strain the bone broth through a sieve, then add the cinnamon, star anise, black cardamom, ginger, and dried onion. Finally, add the beef pho seasoning and adjust the taste to your liking before enjoying.

Finally, just enjoy!